diff options
| author | Marc Zyngier <maz@kernel.org> | 2025-05-13 18:28:16 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2025-05-16 21:32:20 +0200 |
| commit | 06526443a34c06879664eb5ae247c5e93dde7ed9 (patch) | |
| tree | 2c40da6d45cde640cab9dac2b9bd02cf0b56754d | |
| parent | b35961ce0a979fa9c2b0d30a346d3a74ef670aa6 (diff) | |
irqchip/msi-lib: Honour the MSI_FLAG_NO_AFFINITY flag
Bad MSI implementations multiplex MSIs onto a single downstream interrupt,
meaning they have no concept of individual affinity.
The old MSI code did a reasonable job at this by honouring the
MSI_FLAG_NO_AFFINITY, but the new shiny device MSI code doesn't.
Teach it about the sad reality of existing hardware.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250513172819.2216709-7-maz@kernel.org
| -rw-r--r-- | drivers/irqchip/irq-msi-lib.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-msi-lib.c b/drivers/irqchip/irq-msi-lib.c index 2a61c06c4da0..246c30205af4 100644 --- a/drivers/irqchip/irq-msi-lib.c +++ b/drivers/irqchip/irq-msi-lib.c @@ -105,8 +105,13 @@ bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain, * MSI message into the hardware which is the whole purpose of the * device MSI domain aside of mask/unmask which is provided e.g. by * PCI/MSI device domains. + * + * The exception to the rule is when the underlying domain + * tells you that affinity is not a thing -- for example when + * everything is muxed behind a single interrupt. */ - chip->irq_set_affinity = msi_domain_set_affinity; + if (!chip->irq_set_affinity && !(info->flags & MSI_FLAG_NO_AFFINITY)) + chip->irq_set_affinity = msi_domain_set_affinity; return true; } EXPORT_SYMBOL_GPL(msi_lib_init_dev_msi_info); |